Data security using request-supplied keys

This application is a continuation of U.S. patent application Ser. No. 17/177,496, filed on Feb. 17, 2021, entitled “DATA SECURITY USING REQUEST-SUPPLIED KEYS”, which is a continuation of U.S. patent application Ser. No. 16/048,126, filed on Jul. 27, 2018, issued as U.S. Pat. No. 10,936,730, entitled “DATA SECURITY USING REQUEST-SUPPLIED KEYS”, which is a continuation of U.S. patent application Ser. No. 15/090,315, filed on Apr. 4, 2016, issued as U.S. Pat. No. 10,037,428, entitled “DATA SECURITY USING REQUEST-SUPPLIED KEYS,” which is a continuation of U.S. patent application Ser. No. 14/037,292, filed on Sep. 25, 2013, issued as U.S. Pat. No. 9,311,500, entitled “DATA SECURITY USING REQUEST-SUPPLIED KEYS,” the content of which are incorporated by reference herein in their entirety. This application also incorporates by reference for all purposes the full disclosure of U.S. patent application Ser. No. 14/037,282, filed Sep. 25, 2013, issued as U.S. Pat. No. 9,237,019, entitled “RESOURCE LOCATORS WITH KEYS.”

The security of computing resources and associated data is of high importance in many contexts. As an example, organizations often utilize networks of computing devices to provide a robust set of services to their users. Networks often span multiple geographic boundaries and often connect with other networks. An organization, for example, may support its operations using both internal networks of computing resources and computing resources managed by others. Computers of the organization, for instance, may communicate with computers of other organizations to access and/or provide data while using services of another organization. In many instances, organizations configure and operate remote networks using hardware managed by other organizations, thereby reducing infrastructure costs and achieving other advantages. With such configurations of computing resources, ensuring that access to the resources and the data they hold is secure can be challenging, especially as the size and complexity of such configurations grow.

In the following description, various embodiments will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the embodiments may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described.

Techniques described and suggested herein relate to the submission and processing of requests where the requests include cryptographic keys. The requests may be generated by and submitted from customers of a service provider, such as a computing resource service provider. Processing the requests may include use of the keys included in the requests to perform one or more cryptographic operations such as encryption, decryption and generation of electronic (digital) signatures on data. In some embodiments, the techniques described and suggested herein are used to enable server-side encryption (and/or related techniques such as decryption) where the key to be used for encryption/decryption is controlled by the client (i.e. device of the customer or operating on behalf of the customer).

In various embodiments, use of keys provided in requests is performed so that, except for a limited time during which the keys are used, the service provider lacks access to the key. For example, the service provider may operate a data storage service. A customer may transmit data to the service provider for storage by the data storage service. A request to the service provider may include a key to be used to encrypt the data. The service provider may obtain the key from the request and use the key to encrypt the data so that the encrypted data may be persistently stored using the data storage service. When the key is no longer needed (e.g., when encryption of the data has completed), the service provider may perform one or more operations to lose access to the key, such as by destroying or allowing to be destroyed any in-memory copies of the key. Any copies of the data in plaintext form may similarly be destroyed or allowed to be destroyed. Once the key and plaintext data has been destroyed, the customer can be assured that the provider is unable to decrypt the data. Thus, even if a security breach or other event at the provider causes access to the data not authorized by the customer, the breach by itself does not enable access to the data in plaintext form.

Keys may be provided in requests in various ways in accordance with different embodiments. For example, in some embodiments, the request includes the key in plaintext form. The plaintext key may be a symmetric key to be used in a symmetric key algorithm. The plaintext key may also be a public key of a public-private key pair for an asymmetric key algorithm, where the service provider lacks access to the private key of the key pair and the private key is accessible to an entity to be able to decrypt using the private key (e.g., the customer). In some embodiments, requests include keys in encrypted (wrapped) form. For example, the key may be encrypted so as to be decryptable by the service provider or another entity at the direction of the service provider. The key used to encrypt the key in the request may be a secret shared with an entity able to decrypt the key (e.g., service provider) or a public key of a public-private key pair where the private key is to be used by an entity to decrypt the encrypted key for processing the request.

Upon receipt of a request with a key, the service provider may access the key from the request, decrypting or causing to be decrypted, if applicable, and then process the request. Other operations may be performed, such as by verifying an electronic signature of the request or checking whether fulfillment of the request is in compliance with any applicable policy. Other details of operations that may be performed are discussed in more detail below.

shows an illustrative example of an environmentin which various embodiments can be implemented. In the environmenta customertransmits a requestto a service provider. The customer, for example, may utilize services of the service provider. The service provider may provide any type of service relating to data which may be utilized by customers. Example services include data storage services, database services, services that process data and others. To submit a requestto the service providerthe customermay transmit the request with the aid of one or more devices of the customer, such personal or laptop computers, mobile devices, tablet computing devices, electronic book readers and/or others as described in more detail below in connection with. In addition, the requestmay be submitted in accordance with one or more automated processes of the customer. For example, requestmay be transmitted as a result of a human operator of a device of the customerhaving interacted with a browser or other application on a device of the customer. The requestmay be an electronic request transmitted over a network, such as the Internet or any other network or combination of networks discussed below. In some embodiments, for example, the requestis a web service request to a web service interface provided by the service provider. Generally, the requestmay be configured in accordance with various protocols by which requests may be electronically submitted.

As illustrated in, the requestincludes dataand a cryptographic key. The data may include various types of information and may be formatted various ways in accordance with various embodiments. For example, in some embodiments, the data is organized as a file, such as a media file. Data may also be formatted in other ways. The data may be, for instance, organized for inclusion in a database or otherwise. The cryptographic key, as discussed in more detail below, may be a key used to encrypt the dataor otherwise to perform one or more cryptographic operations on data. It should be noted, as will be discussed in more detail below, that the requestmay also include the cryptographic keyin various ways. For example, in some embodiments, the requestincludes the cryptographic keyin plaintext form. In other embodiments, the requestincludes the cryptographic key in encrypted form. For example, as discussed in more detail below, the cryptographic keymay be encrypted by another key such that the service provideror another system associated therewith is able to decrypt the encrypted cryptographic key. In this manner, upon submission of the requestfrom the customerto the service provider, the service providermay use the cryptographic keyto encrypt the datareceived in the requestthereby generating encrypted data.

The encrypted datamay then be stored in a data storage system. The data storage systemwhile illustrated as separate from the service providermay be a subsystem of the service provider. For example, the requestmay be submitted to a web server of the service providerwhere the web server is configured to allow access to the data storage system. Generally, the data storage systemmay be operated as a service to customers such that customers can use resources of the service providerfor the purpose of storing data. Other embodiments also include those in which the data storage systemis separate from the service provider. The data storage systemmay, for example, be operated by an entity that is a third party to the service providerand the customer, or in some embodiments the data storage systemmay be a subsystem of the customer; that is, a subsystem of a system of the customer. It should be noted that terms such as “customer” and “service” provider can have multiple meanings and such meanings are clear from context. For example, the term “customer” may refer to an entity (e.g., a legal entity such as an organization or individual) or a system (e.g., computing device or network of computing devices) that support operations of a customer entity. Similarly, the term “service provider” may refer to a legal entity or a system supporting operations of a service provider entity.

As illustrated in, upon encryption of the datato generate the encrypted data, the service providermay take one or more actions that cause the service providerto lose access to the cryptographic key. This is illustrated inas the service providerpassing the cryptographic keyto an icon labeled as trash. It should be noted that while passing the cryptographic keyinto trash as illustrated in the figure for the purpose of illustration, various embodiments may take action to lose access to the cryptographic keythat do not necessarily involve the transmission of the cryptographic key. For example, in some embodiments, upon receipt of the requestand use of the cryptographic keythe service providermay perform one or more operations to destroy the cryptographic key. Destruction of the cryptographic keymay be performed in various ways in accordance with various embodiments. For example, in some embodiments, the cryptographic keyand requestare not persistently stored by the service providerbut are maintained in volatile memory of a device of a service provider.

Destruction of the cryptographic keymay be performed by allowing one or more memory locations that store the cryptographic keyto be overwritten with other data, such as data received as part of subsequent requests. Other operations may also be performed. For example, if the cryptographic keyis stored in volatile or nonvolatile memory, the cryptographic keymay be destroyed by overwriting (e.g., via one or more write operations intended to destroy the cryptographic key) one or more memory locations used to store the cryptographic keywith other data such as random data or nonrandom data such as a string of zeros. Generally, any operations that will cause the service providerto lose access to the cryptographic keymay be used. In this manner, the customeris able to submit requests to the service providerwith cryptographic keys that the customerdesires to be used to encrypt data. Further, because the service provideris, in various embodiments, configured to lose access to the cryptographic keyafter use of the cryptographic key, the customercan be assured that the service provider, upon processing the request, is unable to access the databy decrypting the decrypted data. In other words, the security of the datais ultimately controlled by the customerwith the service providerhaving access to the data for a limited time.

It should be noted that while various processes resulting in encrypted data (and corresponding decrypting data) are used throughout for the purpose of illustration, the various processes may vary in accordance with other embodiments. For example, example processes for encryption illustrated herein show encryption using a key supplied by a customer of a service provider and where encryption is performed such that after an amount of time the service provider loses access to the key that was used. However, more complex schemes may also be used where more than one key is used to control access to data. For example, referring to, in some embodiments, data may be encrypted using both a key supplied by the customer in a request as well as a key held by or otherwise accessible to the service provider. In this manner, coordinated action between the customerand the service provideris required for access to the databy way of having an ability to decrypt the encrypted data. In some embodiments, for example, the datamay be encrypted with one key and then again encrypted with another key. In other examples, the cryptographic keymay be combined with another key to generate yet another key used to encrypt the data. Such variations may also be extended to multiple parties in addition to the customerand the service providerso that generally coordinated action by a plurality of entities is required for legitimate access to data that has been encrypted, that is to the data in plaintext form. Other variations are also considered as being within the scope of the present disclosure.

In addition, while various embodiments described herein illustrate requests that have certain types of data, requests may include other types of data. For example, requests my include data for various parameters of the request which may be used by a service provider to determine if, and/or how to, fulfill a request. Generally, requests as discussed herein are simplified for the purpose of illustration. The requests may, for instance, include various contextual data such as an identity of a requestor, a network address from which the request originates, an identity of an entity that generated some or all of the request and/or other types of data.

Further, it should also be noted, that whileshows the requesthaving datato be encrypted, requests within the scope of the present disclosure do not necessarily have data to be encrypted. For example, in some embodiments the requests may have a reference to data (e.g., an identifier of a data object, which may be in the form of a URL) that is not necessarily included in the request. Processing such a request may include using the reference to obtain the data. As another example, some requests may lack data because the requests include retrieval of data as one or more requested operations. A request to retrieve data may include a cryptographic key, but the data may be stored in another location. Processing the request may include accessing encrypted data to decrypt using the cryptographic key provided in the request. Other variations are also considered as being within the scope of the present disclosure.

shows an illustrative example of an environment of a service providerin accordance with various embodiments. As illustrated in, the service providerincludes a customer interface. The customer interface may be a subsystem of the service providerwhich allows for the submission of requests from customers to be processed by the service providersuch as described above in connection with. The customer interface may accordingly include appropriate computing devices for providing the ability for customers to submit requests to the service provider. This customer interface, for example, may include one or more web servers configured to receive requests over the internet or another network. While not illustrated as such, other infrastructure may also be included in the customer interface, such as appropriate networking equipment that enable the customer interfaceto operate suitably for the customer of the service provider.

When a request is received through the customer interface, the request may be received with appropriate authenticating information. For example, as illustrated in, a requestmay be received with a signatureof the request. The signature may be generated in accordance with various embodiments. For example, a customer that submitted the requestmay generate the signatureusing secret information shared between the customer and the service provider. As another example, a customer may have used an asymmetric digital signature scheme to sign the requestusing a private key of a private/public key pair. Generally, any type of information which is used to authenticate the requestmay be used and, in some embodiments, requests may be submitted without such information. Further, in some embodiments, the electronic signature of a request is generated using a cryptographic key that is different than a cryptographic key supplied in the request, although in some embodiments, the electronic signature is generated using the same key that is supplied in the request.

As illustrated in, however, when a requestis received through the customer interface, the requestis provided (e.g., over an internal network of the service provider) with the signatureto an authentication systemof the service provider. Alternatively, a portion of the request sufficient for generating the electronic signaturemay be provided instead of the whole request. The authentication systemmay be a subsystem of the service providerconfigured to authenticate requests such as by verifying electronic signatures provided with requests. Upon verifying the signatureof the requestthe authentication systemmay provide a response to the customer interfacethat indicates whether the signatureis valid. A device of the customer interfacemay use the information provided by the authentication systemin order to determine how to process the request. For example, if the authentication systemindicates that the signatureis invalid, the customer interfacemay deny the request. Similarly, if the information from authentication systemindicates that the signatureof the requestis valid, the customer interfacemay cause the requestto be processed.

While not illustrated in the figure, the authentication systemor another system operating within or on behalf of the service providermay operate to perform other operations in connection with determining how to process requests. For example, the authentication systemor another system operating in cooperation therewith may be used to check one or more policies which may be determinative of whether the request can be fulfilled. Policy determinations may be made based at least in part on various factors such as an identity of the requestor that submitted the request, a time of day, a logical identifier for a location in which data is stored or is to be stored and other contextual information. Policy may be managed through the customer interfaceor another interface through appropriately-configured application programming interface (API) calls.

Returning to the embodiment illustrated in, if the authentication systemdetermines that the signatureis valid, the customer interfacemay determine to process the request. Processing the request may involve the transfer of encrypted databetween the customer interfaceand request processing infrastructure. The request processing infrastructuremay comprise one or more devices that collectively operate to provide a service of the service provider. For example, as illustrated in, the request processing infrastructure may comprise a plurality of data storage systemused to store data on behalf of customer of the service provider. Other infrastructure including networking infrastructure while not illustrated may also be included. The passage of data, e.g., over a network between the customer interfaceand the request processing infrastructuremay occur in various ways in accordance with various embodiments in accordance with the various types of requests that may be submitted through the customer interface. For example, if the requestis a request to store data, a customer interface may utilize a key provided in the requestto encrypt the data and transmit the encrypted datato the request processing infrastructurefor storage in one or more of the data storage systems.

Similarly, if the requestis a request to retrieve data, a customer interfacemay transmit a communication to the request processing infrastructurethat allows data from one or more of the data storage systemsto be provided to the customer interface. The customer interfacemay then use a key provided in the requestto decrypt the encrypted dataand provide the decrypted data to the customer that submitted the request. It should be noted that the environment of the service providerillustrated inis simplified for the purpose of illustration and that numerous other devices and subsystems such as accounting systems that keep track of usage of the service providerby customers may also be included. Further, a service providermay include facilities located in different geographical locations for the purpose of redundancy and/or availability.

shows an illustrative example of a requestin accordance with various embodiments, where the request may be a request such as described above in connection with. As illustrated in the example shown in, the requestincludes a symmetric key which may be a cryptographic key used for both encryption and decryption of data. In an embodiment, the symmetric keyof the requestis provided in the requestin plaintext form. It should be noted that while the symmetric key is provided in the requestin plaintext form in some embodiments, the transfer of a request from a customer to a service provider or generally between entities may involve various protocols to ensure security of any data in the request. For example, transmission of the requestmay involve transport layer security (TLS) and/or another protocol such that the symmetric keyis encrypted during transmission from one entity to the other. Further, whileshows a requesthaving a symmetric keythe requestmay include other data which is not illustrated in the figure. Such data as discussed above may include various request parameters, authentication information, data to be encrypted, and/or other information.

In addition, whileshows a request with a key, as with all requests described and illustrated herein, various other data may be provided within the request, such as data to be operated on and/or various metadata including contextual information about the request and authentication information usable to verify authenticity of the request. Various request parameters may also be included in the request. For instance, a request parameter may specify that server side encryption is supposed to be used to encrypt data using a key provided with the request. If such a parameter is absent and/or indicates that server side encryption is not to be used, the request may be processed without encryption being performed regardless of whether a key is included in the request. Further, for requests submitted with electronic signatures, a parameter may specify which part of the request was used to generate an electronic signature. Such a parameter can indicate which part of a request should be used for checking an electronic signature, thereby enabling requests to be modified after their generation, such as by adding data to be operated on during fulfillment of the request. Generally, requests are simplified in the present disclosure for the purpose of illustration.

shows an illustrative example of a processwhich may be used to transmit and receive a response to a request in accordance with various embodiments. The processmay be performed by any suitable system such as a device of a customer such as described above and below in connection with. In an embodiment, the processincludes obtaininga cryptographic key. The cryptographic key may be obtainedin various ways in accordance with various embodiments. For example, in some embodiments the cryptographic key is obtainedby generating the cryptographic key. The cryptographic key may be generated for example using a random number generator or a key derivation function such as public key derivation function 2 (PPKDF2) or Bcrypt. The cryptographic key may be obtainedin other ways as well. For example, the cryptographic key may be accessed from a data storage device. As another example, the cryptographic key may be a password, passphrase, or other type of passcode accessed from memory and/or input by a user of a system performing the process. Generally, any way of obtaininga cryptographic key may be used.

With the cryptographic key having been obtained, the processmay include generatinga request with the obtained cryptographic key; that is, generating a request that includes the obtained cryptographic key. The request may be generated by arranging data for the request in a manner suitable for transmission that is in a format processable by a system to which the request will be submitted. Once generated, the generated request may be submitted. Submissionof the generated request may be performed in any suitable manner such as by transmission to an Internet protocol (IP) address of a webserver configured to receive generated requests. Other operations may be performed, for example, in some embodiments the request is generated from a uniform resource locator (URL). Communication with the domain name service (DNS) may occur to obtain an IP address for the system to which the generated request is then submitted. Generally any way of submitting the request may be performed.

Upon submission, a request may be processed by a system to which the generated request was submitted. Accordingly, the processmay include receivinga response to the request or the response may be an appropriately configured response in accordance with a protocol by which the request was submitted. It should be noted that not all embodiments require receipt of a response to the request. For example, some protocols may allow for the submission of requests without acknowledgement that the request has been received and/or fulfilled. As an illustrative example, the request may be to store data. In some embodiments, upon submission it may be assumed that the request has been processed or likely had been processed where acknowledgement of processing of the request may not be required.

shows an illustrative example of a processfor processing a request where the request may be received such as described above and may have been submitted in accordance with a process such as the processsuch as described above. The processmay be performed by any suitable system such as by a device (e.g., server) operating to provide a customer interface such as described above. In an embodiment, the processincludes receivinga request with a cryptographic key. The request may be receivedin various ways in accordance with various embodiments. For example as noted above, the request may be submitted over a network in accordance with a communication protocol and the request may therefore be received in accordance with such a protocol. Generally the request may be receivedin any suitable way.

Upon receipt of the request, the processmay include determiningwhether to fulfill the request. The determinationwhether to fulfill the request may be made in various ways in accordance with various embodiments. For example as noted above, in some instances the request may be received with an electronic signature of the request. Accordingly, a determination may be made by determining whether the signature is valid. Determination of whether the signature is valid may be performed in various ways. For example, the system performing the processmay verify the signature itself or may transmit the signature and request (or generally data signed to generate the signature) to another system operable to verify the electronic signature. Further as noted above, determiningwhether to fulfill the request may include performing a determination whether one or more policies would preclude fulfillment of the request. Generally any way by which a determination of whether to fulfill the request may be performed.

In addition, whileand other processes illustrated herein show determinations whether to fulfill the request, in various embodiments, systems may fulfill all appropriately configured requests without the need to have a valid electronic signature and/or compliance with policy. Returning to the embodiment illustrated in, if it is determinednot to fill the request such as if a signature is invalid and/or policy precludes fulfillment of the request, the processmay include denyingthe request. Denyingthe request may be performed in various ways in accordance with various embodiments. For example, a response to the request may be provided that indicates that the request is denied and/or that provides information why the request was denied. As another example, denying the request may simply be performed by not taking any action. That is by not providing a response to the request and simply not fulfilling the request. Generally any way in which the request may not be fulfilled may be considered as denying the request.

If it is determined, however, to fulfill the request, the processmay include extractinga cryptographic key from the request. The extracted cryptographic key may then be usedto perform one or more requested cryptographic operations; that is to perform one or more cryptographic operations involved in fulfillment of the request. The one or more cryptographic operations may vary in accordance with various embodiments and in accordance with the type of request that was received. In some embodiments for example, the one or more cryptographic operations include encryption of data included with the request and/or encryption of other data. As another example, the one or more cryptographic operations may include decryption of data referenced by and/or provided in the request. Generally any type of cryptographic operations such as key derivation and/or electronic signature generation and/or verification may be performed as part of the one or more cryptographic operations. Further, while various illustrative embodiments described herein show a single cryptographic operation such as encryption, multiple types of cryptographic operations may be performed while fulfilling a single request. As an example, one or more keys provided in a request may be used to encrypt data and generate an electronic signature of the data and/or encrypted data where the electronic signature can be used for later validation that the data has been changed. Other variations are also considered as being within the scope of the present disclosure.

Upon performance of the one or more cryptographic operations, the processmay include providinga response to the request. The response may vary in accordance with the various embodiments and in accordance with the type of request that was made. For example, if the request was to retrieve data, the response may include data that was retrieved and decrypted. If the request was to store data, the response may be an acknowledgement that the data has been stored. A check sum or other validation information may be provided with the response. At some point subsequent to performance of the one or more cryptographic operations involved in fulfillment of the request, the processmay include losingaccess to the extracted cryptographic key where access may be lost in various ways such as described above.

is an illustrative example of a requestin accordance with various embodiments. As illustrated in, unlike the request described above in connection with, the requestincludes a customer public keywhich may be a public key of a public/private key pair where the private key is held by or on behalf of the customer. As with other requests described herein, the requestmay include other data such as described above. The requestmay be submitted such as described above in connection with.

shows an illustrative example of a processwhich may be used to process a request that includes a customer public key such as described above in connection. The processmay be performed by any suitable system, such as a system providing a customer interface such as described above. As illustrated in, the processincludes receivinga PUT request with a customer public key; that is a PUT request (i.e., a request to store data) that has, as part of the request, a customer public key. The request may be receivedsuch as described above and generally in any suitable manner. Upon receiptof the PUT request with the customer public key the processmay include determiningwhether to fulfill the request where the determination whether to fulfill the request may be made such as described above. If it is determinedthat the request should not be fulfilled, the processmay include denyingthe request such as described above. If, however, it is determinedthat the request should be fulfilled, the processmay include extractinga customer public key from the request for use. In an embodiment, the processincludes obtainingan encryption key where the encryption key may be a symmetric key such as described above. The encryption may be obtainedin any suitable manner such as described above. For example, the encryption key may be accessed from data storage or generated. The obtainedencryption key may be usedto encrypt data that was provided in the request or otherwise requested by the request to be encrypted. The customer public key may be usedto encrypt (wrap) the encryption key. In this manner, the encrypted encryption key is decryptable using a private key corresponding to a customer public key. Thus, if a provider performing the processdoes not have access to the encrypted encryption key, the provider cannot decrypt the encrypted encryption key.

The processmay also include storingthe encrypted data. The encrypted data may be, for example, transmitted to a data storage system for persistent storage thereof. A response to the request may be providedwhere the response may include the encrypted encryption key. A system performing the processmay loseaccess to the encryption key such as described above. In this manner, once a system performing the processlosesaccess to the encryption key, the system no longer has the ability to decrypt the encrypted data and generally use of a private key corresponding to the customer public key is necessary to legitimately (i.e., without guessing the key or otherwise obtaining access to the data in an unauthorized manner) decrypt the encrypted data by first decrypting the encryption key in order to decrypt the decrypted data.

It should be noted, as with all processes described herein, variations are considered as being within the scope of the present disclosure. As an example,shows a process for processing a PUT request where the request includes a customer public key. Such request can be processed in different ways in accordance with various embodiments. In some embodiments for example, although use of a symmetric encryption key is generally computationally more efficient, a customer public key may be used to encrypt the data that was received in the request instead of using an encryption key that is then wrapped by the public key. In this manner, the data is decryptable only by an entity having access to the private key corresponding to the customer public key, which in various embodiments may be only the customer that submitted the request.

As another example of a variation considered as being within the scope of the present disclosure, the encrypted encryption key may be stored with the encrypted data and may or may not be transmitted in a response to the request. In such an embodiment to decrypt the data, the encryption key may be accessed from storage provided to an entity able to decrypt the encryption key (e.g., customer having a private key usable to decrypt the encryption key) which may then provide the decrypted encryption key back to enable decryption of the data. For example, a customer request to retrieve data may cause a provider to transmit an initial response with notification (including the encrypted encryption key) that the encryption key needs decrypting. The customer may decrypt the encryption key and provide the decrypted encryption key back to the provider to enable the provider to decrypt the encrypted data and provide the decrypted data to the customer. Other variations, including variations where ciphertext is provided to the customer from the provider along with an encrypted key usable to decrypt the ciphertext, are also considered as being within the scope of the present disclosure. For embodiments where, for example, server side encryption is used to PUT requests but client side encryption is used to obtain access to stored data, a provider may provide instructions for properly processing data (e.g., by properly canonicalizing data for decryption) or may provide executable instructions in the form of a client library to ensure that decryption is performed correctly (i.e., to ensure that decryption is performed in a manner that will succeed in decrypting the data).

shows an illustrative example of a processfor obtaining data that has been stored in encrypted form by another system such as by a provider such as described above. The processmay be performed by any suitable system, such as by a device of a customer of a provider such as described above. In an embodiment, the processincludes obtainingan encrypted encryption key. For example, the encrypted encryption key may have been received pursuant to performance of the processdescribed above or a variation thereof. Obtaining the encrypted encryption key may include receiving the encrypted encryption key or accessing the encrypted encryption key from persistent data storage. Generally the encrypted encryption key may be obtainedin any suitable manner.

A private key corresponding to a public key used to encrypt the encryption key may be usedto decrypt the encrypted encryption key. Once the decrypted encryption key has been obtained, the processmay include generatinga GET request with the decrypted encryption key and submitting (e.g., transmitting)the generated GET request, such as described above. A system that receives the GET request may process the request by using the encryption key in the request to decrypt data that was encrypted by the encryption key. A response may then be receivedwhere the response may include appropriate information such as data that has been decrypted using the decrypted encryption key that was provided in the GET request.

As with all processes described herein, variations of the processare considered to be within the scope of the present disclosure. For example, the encrypted encryption key may be obtained by accessing the encrypted encryption key from remote storage when the encrypted encryption key is stored with the data that is encrypted under the encrypted encryption key. As another example, in some embodiments the processmay include submitting a GET request that is fulfilled by providing data encrypted under the encrypted encryption key. A system performing the processmay obtain the encrypted data and use the decrypted encryption key to decrypt the encrypted data. In other words, the processmay be modified so that data is decrypted client-side even if the data was encrypted server-side.

shows an illustrative example of various requests that may include cryptographic keys that have been wrapped (i.e., encrypted) in various forms in accordance with various embodiments. For example,shows an illustrative example of a requesthaving a symmetric keyencrypted under a secretshared with a provider where the secret shared with the provider may be another symmetric key shared between the customer and the provider. As another example,shows an example of a requestthat includes a symmetric keyencrypted under a provider public keywhich may be a public key corresponding to a public private key pair of which the provider has access to a corresponding private key. Another requestincludes a symmetric keyencrypted under a secretshared with a third party. That is an entity that is a third party to both a customer and a provider. As yet another example,shows a requesthaving a symmetric keyencrypted under a public keyof a third party where the third party may be a third party to a customer and provider. As noted, the requests illustrated inmay also include additional information.

shows an illustrative example of a processwhich may be used to submit a request in accordance with various embodiments. The processmay be performed by any suitable system such as by a system of a customer of a provider such as described above. In an embodiment, the processincludes obtaininga cryptographic key where the cryptographic key may be obtainedsuch as described above. The obtained cryptographic key may be used to generatea wrapped cryptographic key that is the obtained cryptographic key encrypted under another key. Examples of wrapped cryptographic keys are described above in connection with. The processmay include generatinga request with the wrapped cryptographic key. That is the request may be generated to include the wrapped cryptographic key. The generated request may then be submittedsuch as described above. In various embodiments, the processmay also include receivinga response to the request that was submitted.

As noted above, numerous embodiments are considered as being within in the scope of the present disclosure. In some embodiments, a customer and service provider are able to interact to achieve data security without use of a third party system to unwrap a key needed for cryptographic operations.accordingly shows an illustrative example of an environmentin which various embodiments can be practiced. As with, as illustrated in, the environmentincludes a customerthat submits a requestto a service provider. In this example, the requestincludes an encryption keywhich, as indicated by the brackets surrounding the encryption key, is wrapped by another key. The service providerhas access to a keyusable to unwrap the encryption key thereby enabling the service providerto perform cryptographic operations using encryption key.

shows an illustrative example of a processwhich may be used to process a request that includes a wrapped cryptographic key. The processmay be performed by any suitable system such as by a webserver of a service providerdescribed above in connection with. In an embodiment the processincludes receivinga request that has a wrapped cryptographic key. A determination may be madewhether to fulfill the request. If determinedto not fulfill the request, the processmay include denyingthe request such as described above. If, however, it is determinedthat the request should be fulfilled, the processmay include extractingthe wrapped cryptographic key from the request.

A key usable to unwrap the cryptographic key may be obtained. Obtaining the key usable to unwrap the cryptographic key may be performed in various ways in accordance with various embodiments. For example, the key usable to unwrap the wrapped cryptographic key may be stored by a system that performs the process. An identifier of the key usable to unwrap the wrapped cryptographic key may be used to locate the key usable to unwrap the wrapped cryptographic key from other keys which may be stored by the system. The identifier may be provided in the request that was receivedor may be otherwise determined such as by an association with an entity that submitted the request. Once the key usable to unwrap the wrapped cryptographic key has been obtained, the processmay include usingthe obtained key to unwrap the wrapped cryptographic key. In this manner, an unwrapped cryptographic key is obtained. The unwrapped cryptographic key may be usedto perform one or more cryptographic operations involved in fulfillment of the request that was received. A response to the request may be providedsuch as described above and access to the unwrapped cryptographic key may be lost.

In some embodiments, as noted, involvement of a third party is part of maintaining data security.accordingly shows an illustrative example of an environmentwith various embodiments can be practiced. The environmentas illustrated includes a customerthat submits a requestto a service providersuch as described above. Also as described above, the requestmay include an encryption keythat is wrapped by another key such as described above in connection with. However, in the example of, a subsystem of the service providerthat receives the request (or, in some embodiments, all subsystems of the service provider) may not have access to a key usable to unwrap the encryption key. Accordingly, the environmentincludes a key management systemwhich has access to a keyusable to unwrap the wrapped encryption key. The key management systemmay be any system operable to manage cryptographic keys on behalf of one or more customers of the service provider.

The key management systemmay be implemented in various ways in accordance with various embodiments. In some embodiments, the key management system is a subsystem of the service providerwhich may be implemented by, for instance, a hardware security module (HSM) hosted by the service provideror another type of security module that securely stores cryptographic keys. In some embodiments, the key management systemis implemented as another service of the service providerwhich may be one of several services provided by the service providerand accessible to customerover a network such as described below. In some embodiments, the key management system is a system such as described above, however, implemented by a third party to the service providerand customer. In such embodiments, neither the customernor the service providerhas access to the key usable to unwrap the encryption keyunless the keyusable to unwrap the encryption key is shared with one or more of the customeror service provider. Other variations are also considered as being within the scope of the present disclosure. For example, the key management systemmay be implemented as part of the customerin some embodiments. Generally, the key management systemis a system with which the service providermust communicate in order to unwrap or generally cause to have unwrapped the encryption keyusing the keyusable to unwrap the encryption key. Communication between the service providerand the key management systemmay occur over one or more networks and in accordance with one or more appropriate network protocols. The network may be, for example, the Internet or any suitable network such as described below.

shows an illustrative example of a processwhich may be performed to process a request that includes a wrapped encryption key such as described above in connection with. In an embodiment, the processincludes receivinga request with the wrapped cryptographic key such as described above. As discussed above in connection with other processes, a determination may be madewhether to fulfill the request, and if determinedthat the request should not be fulfilled the processmay include denyingthe request. If, however, it is determinedthat the request should be fulfilled, the processmay include extracting the wrapped cryptographic key from the request. The wrapped cryptographic key may be transmittedto an unwrapping system which may be a key management system such as described above as in connection withand generally which may be a system with access to a key usable to unwrap the wrapped cryptographic key.

The wrapped cryptographic key may be transmitted in the form of a request to the unwrapping system which is appropriately configured for fulfillment by the unwrapping system. For example, the request may be formatted in accordance with a format acceptable to the unwrapping system and the request may include information usable by the unwrapping system to determine whether to fulfill the request. Such information may include, for example, authentication information used to authenticate the request to the unwrapping system and/or the request that was receivedwith the wrapped cryptographic key. Other information which may be used, for example, to determine whether fulfillment of the request to the unwrapping system complies with one or more policies may also be provided or the information may be contextual information such as described above. Additional information may include an identifier of a key usable to unwrap the wrapped cryptographic key. Assuming that the unwrapping system fulfills the request that was transmitted, the processmay include receivingthe unwrapped cryptographic key from the unwrapping system. The unwrapped cryptographic key may be usedto perform one or more cryptographic operations involved in fulfillment of the request that was received. As response to the request may be providedsuch as described above and access to the unwrapped cryptographic key may be lost, such as described above.

As noted several times throughout the above disclosure, numerous variations are considered as being within the scope of the present disclosure. For example, as discussed, numerous variations utilize symmetric and/or asymmetric cryptographic primitives. Symmetric key algorithms may include various schemes for performing cryptographic operations on data including block ciphers, stream ciphers and digital signature schemes. Example symmetric key algorithms include, but are not limited to, the advanced encryption standard (AES), the data encryption standard (DES), triple DES (3DES), Serpent, Twofish, blowfish, CASTS, RC4 and the international data encryption algorithm (IDEA). Symmetric key algorithms may also include those used to generate output of one way functions and include, but are not limited to algorithms that utilize hash-based message authentication codes (HMACs), message authentication codes (MACs) in general, PBKDF2 and Bcrypt. Asymmetric key algorithms may also include various schemes for performing cryptographic operations on data. Example algorithms include, but are not limited to those that utilize the Diffie-Hellman key exchange protocol, the digital signature standard (DSS), the digital signature algorithm, the ElGamal algorithm, various elliptic curve algorithms, password-authenticated key agreement techniques, the pallier cryptosystem, the RSA encryption algorithm (PKCS #1), the Cramer-Shoup cryptosystem, the YAK authenticated key agreement protocol, the NTRUEncrypt cryptosystem, the McEliece cryptosystem, and others. Elliptic curve algorithms include the elliptic curve Diffie—Hellman (ECDH) key agreement scheme, the Elliptic Curve Integrated Encryption Scheme (ECIES), the Elliptic Curve Digital Signature Algorithm (ECDSA), the ECMQV key agreement scheme and the ECQV implicit certificate scheme. Other algorithms and combinations of algorithms are also considered as being within the scope of the present disclosure.

In addition, as noted, various embodiments of the present disclosure relate to the use of cryptographic keys included in requests to perform various cryptographic operations. While the keys are discussed as being used to perform the operations, it should be noted that various embodiments of the present disclosure include those where keys are transformed in some way before being used. As an example, in cases where a key in a request is a passcode, the passcode may be transformed (e.g., with a key derivation function) before being used to perform additional cryptographic operations. Further, while the above disclosure discusses specific types of keys (e.g., encryption keys) such keys may similarly be transformed before use. Other variations include those where multiple keys are provided in requests and request parameters and/or formatting of the request indicate how the multiple keys should be used.